Bally Rapid Fire pinball help

[Lindsey]

yea, it really strikes me that I had the very same problem on the bench with a bad ground as I did with the MPU in the backbox.
After I connected everything up on the bench the LED was stuck high or on. Then I would short 39 and 40 on the CPU and that would reset it. It would flash 6 times and go out. I'll have to look up this DS1811 reset circuit conversion.
No those readings can't be right. Going to mess with it some more here.

Like I said above, pin 40 (reset) of the CPU should go low briefly then high when you apply power to the board. I suspect that is either not happening or not happening for long enough because the MPU will boot with a manual reset.

If you have access to the old pinrepair.com there is a good section on installing a DS1811. I really need to put together something for my site on that conversion because I get asked about it a lot. Compared with rebuilding the original reset circuit it's a much better option.

 

[Zinfer]

I'm thinking I'm just not getting proper voltages from the solonoid driver/voltage regulator module. Replaced Q1 transistor on MPU. No change. I don't have a Q5 or I'd have changed that out. I sanded the edges of the MPU to try and get any remaining corrosion off.
I'll run some voltage checks on the taps of the solonoid tonight.

 

[Lindsey]

Well, I was doing some reading about that. And in my case, if +12v is not present then the LED will be off all the time.

That's right. The LED is powered by +12V. The ground side goes through a transistor that is biased (turned on or off) but a PIA output (U11 pin 39). That's how the CPU is able to turn the LED on or off.

I thought it was something like Pin 9 of J4 that held the +12v. Where does that +12 come from?

+12V comes in to the MPU on pin 12 of connector J4. The +12V seems unlikely to be the problem.

hmm. Filter cap.

If the filter cap for the +5VDC (C23 on the regulator/driver board) is original it should be replaced as a preventative maintenance measure but the fact that you have to manually reset the MPU to get it to boot tells me that a problem with the reset circuit is what's stopping the MPU from booting. Especially since (I think) you said you could get it to boot in the machine with a manual reset. At a minimum there is a reset problem.

Are the +12v and +5v coming from the transformer under the cabinet or from the PS to the right in the backbox?

Both voltages come from the regulator/driver board. The +5VDC is regulated and the +12VDC is not. That's important to note because the unregulated voltage will have a lot high acceptable variation in the voltage.

 

[Zinfer]

No, my problem is I cannot get the MPU to boot at all in the machine. The MPU is always dead in the machine. On the bench I did with an AT PS +12v +5v directly wired to the Taps. On the bench the LED was lit until I reset by crossing pins 39 & 40 of the CPU. Then I got the 6 flashes. Without the presence of +12v, it's not even activating the LED. And correct me if I'm wrong, but it must detect the presence of +12v before a reset/boot signal is even sent.
Regardless, I'll probably put in an order for the 5v and the HV regulator kits. Some 40$ plus shipping. Prolly silly but I don't have the extra boards to test with. Like you said, good idea to update the caps anyways.
I'd still like to take some measurements at the solonoid/regulator board.
I've only tried everything with just J4 connected for isolation, but it's still getting it's voltages from the solonoid/regulator board.
(*Updated*) Checked voltages of all taps on Solonoid/regulator pcb. No presence of anything near +12 or +5v. After receiving and installing the regulator kits and if it's still behaving this way = I would think my next stop should be the rectifier.


If the filter cap for the +5VDC (C23 on the regulator/driver board) is original it should be replaced as a preventative maintenance measure but the fact that you have to manually reset the MPU to get it to boot tells me that a problem with the reset circuit is what's stopping the MPU from booting. Especially since (I think) you said you could get it to boot in the machine with a manual reset. At a minimum there is a reset problem.
Both voltages come from the regulator/driver board. The +5VDC is regulated and the +12VDC is not. That's important to note because the unregulated voltage will have a lot high acceptable variation in the voltage.[/QUOTE]

 

[Lindsey]

I wouldn't trust that meter until I verified it with a known good one. Those readings don't make sense and I'm willing to bet your meter is at fault. If it's a cheap meter the batteries are probably nearly dead. There's no sense replacing the +5V regulator or shotgunning anything until you can get some proper voltage readings. If the readings you mention above were correct there would be smoke pouring out of the boards when you turned the game on.

Of course, that doesn't explain why the game won't boot and it's probably related to the +5V, but I would still figure out why you're getting those crazy voltage readings.

 

[Zinfer]

Yea, so true. I'll trust a tool only so far. But when you start getting readings like 80 volts instead of +5v and your not seeing cooking IC's, smoke and fire you pretty much know somethings out of whack.
By no means top of the line, I've always had good experiences with it as a mid-range. It's a Craftsman autoranging Multimeter 82139. I'll change the batteries today. It had a pair of Duracell AAA's - it has autoshutoff. The batteries were still good, but I'll take this opportunity to change them out. One of the 10A mini-fuses were blown, but it was on the other side of the COM that I wasn't using. Always been a pretty trusty helper. Maybe something throwing off the autoranging on that circuit is all I can think of. I'll throw in a new set of batteries and a 10a fuse today. But it's my only meter. I've seen some out there I'd like to have but they're pretty expensive. Of the type I'd be afraid to use.
Maybe I could have a friend come over tonight, he usually has the newest leather bag kept non-used meter. I'll try a second set of readings at those taps. I don't think it's something I'm doing wrong. Just set for VDC, ground to ground and hot to taps. Pretty straight forward.

I wouldn't trust that meter until I verified it with a known good one. Those readings don't make sense and I'm willing to bet your meter is at fault. If it's a cheap meter the batteries are probably nearly dead. There's no sense replacing the +5V regulator or shotgunning anything until you can get some proper voltage readings. If the readings you mention above were correct there would be smoke pouring out of the boards when you turned the game on.

 

[Lindsey]

Yea, so true. I'll trust a tool only so far. But when you start getting readings like 80 volts instead of +5v and your not seeing cooking IC's, smoke and fire you pretty much know somethings out of whack.
By no means top of the line, I've always had good experiences with it as a mid-range. It's a Craftsman autoranging Multimeter 82139. I'll change the batteries today. It had a pair of Duracell AAA's - it has autoshutoff. The batteries were still good, but I'll take this opportunity to change them out. One of the 10A mini-fuses were blown, but it was on the other side of the COM that I wasn't using. Always been a pretty trusty helper. Maybe something throwing off the autoranging on that circuit is all I can think of. I'll throw in a new set of batteries and a 10a fuse today. But it's my only meter. I've seen some out there I'd like to have but they're pretty expensive. Of the type I'd be afraid to use.
Maybe I could have a friend come over tonight, he usually has the newest leather bag kept non-used meter. I'll try a second set of readings at those taps. I don't think it's something I'm doing wrong. Just set for VDC, ground to ground and hot to taps. Pretty straight forward.

You can be sure there are probably connector issues too. The whole thing could come down to a bad pin in J4 on the MPU. Once the issue of wacky voltages is solved it should be pretty straight forward from there.

 

[Zinfer]

One thing I'm uncertain about is that blue wire that's leading to J4 if you relook at the pics. I'm not sure why he's running it to a board ground at the opposite end of the board. That is just odd looking. It involves like 2 or 3 pins he's soldered it to and then ran the other end to solder at where the board fastens to the mount bracket in the backbox.

 

[Robran68]

One thing I'm uncertain about is that blue wire that's leading to J4 if you relook at the pics. I'm not sure why he's running it to a board ground at the opposite end of the board. That is just odd looking. It involves like 2 or 3 pins he's soldered it to and then ran the other end to solder at where the board fastens to the mount bracket in the backbox.

Hey Rod, if you have or know anybody with a 77'-85' Bally pin you can test that MPU in it. I do it all the time in my Black Pyramid. That way you can isolate it to the MPU if you know all the molex connectors, power supply, and wiring is good.

 

[Zinfer]

Absolutely, yea that'd be super. Having spares is always a plus. I was looking at some prices on ebay for an MPU and whew! I guess my issue is I just bought this so I can't vouch for the rectifier, the wiring looks good. I haven't followed the connectors. I have yet to figure out just why the playfield doesn't have a stick or something to hold it up kind of like a car hood. Or am I just supposed to like, unplug it and pull it out altogether? I took more readings tonight but my friend didn't show up with his meter so I have nothing new to report on it. I ordered a hundred 3906 transistors so now I can replace Q5 when they come in. I took more reading on the Solonoid driver board and the MPU. I'll post those when I can confirm them with another meter.
It bothers me with that blue wire hack job at J4. Going to figure a way to take readings directly from the J4 connector. But I have yet to find ANY Pinouts of J4 other than pin 12 being +12v. And I'm certainly not driving to Michigan to find out if my MPU is junk. Perhaps if you were selling an Sega Eliminator for $100 or something.
There is someone about an hour from me that may drop by if I asked him. He might have one. That is a good idea.
Going to try a few more things yet, bounce my head against a wall, endure the pain some more before I'm ready to say Hey - are there any MPU repair people out there?

Hey Rod, if you have or know anybody with a 77'-85' Bally pin you can test that MPU in it. I do it all the time in my Black Pyramid. That way you can isolate it to the MPU if you know all the molex connectors, power supply, and wiring is good.

 

[Angry_Radish]

My Rapid Fire is currently torn apart while I'm rebuilding the ball feeder mech, but if you are still having issues once I get it back together I'd be more than happy to do some apples to apples voltage comparisons.

 

[Lindsey]

Absolutely, yea that'd be super. Having spares is always a plus. I was looking at some prices on ebay for an MPU and whew! I guess my issue is I just bought this so I can't vouch for the rectifier, the wiring looks good. I haven't followed the connectors. I have yet to figure out just why the playfield doesn't have a stick or something to hold it up kind of like a car hood. Or am I just supposed to like, unplug it and pull it out altogether? I took more readings tonight but my friend didn't show up with his meter so I have nothing new to report on it. I ordered a hundred 3906 transistors so now I can replace Q5 when they come in. I took more reading on the Solonoid driver board and the MPU. I'll post those when I can confirm them with another meter.
It bothers me with that blue wire hack job at J4. Going to figure a way to take readings directly from the J4 connector. But I have yet to find ANY Pinouts of J4 other than pin 12 being +12v. And I'm certainly not driving to Michigan to find out if my MPU is junk. Perhaps if you were selling an Sega Eliminator for $100 or something.
There is someone about an hour from me that may drop by if I asked him. He might have one. That is a good idea.
Going to try a few more things yet, bounce my head against a wall, endure the pain some more before I'm ready to say Hey - are there any MPU repair people out there?

Making a trip to someone's house to test the MPU in their machine is going to be a complete waste of time (IMO). Here's what will happen: it will either boot fine or boot fine with a manual reset. There, I saved you the time You already tested it. You know yours will boot with a manual reset on a bench. I wouldn't be surprised if it boots fine once your connector or voltage issues are resolved. MPUs often require manual reset with PC power supplies but will boot fine with the original linear supply (assuming it's working properly). At this point we can be fairly certain that the problem is related to connectors, power supply or both (and possible reset issues or continuing corrosion related issues).

What you really need to do is figure out why you're getting those weird voltage readings, repair any problems that you might have with the power supply and ensure there are good connectors between the power supply and MPU.

You can find the pinout of J4 on the schematic which will be in the manual. If it's not in the Rapid Fire manual it will be in the manual for one of the other games using a -35. I usually use a Mr. & Mrs. Pacman manual when working on -35 games.

If your MPU boots on the bench with a manual reset but won't boot in the game with a manual reset then we can deduce that you have a problem other than the MPU itself.

Rapid Fire manual (MPU schematic):
http://www.ipdb.org/files/3568/Bally_1982_Rapid_Fire_Operations_Manual.pdf

 

[Lindsey]

One thing I'm uncertain about is that blue wire that's leading to J4 if you relook at the pics. I'm not sure why he's running it to a board ground at the opposite end of the board. That is just odd looking. It involves like 2 or 3 pins he's soldered it to and then ran the other end to solder at where the board fastens to the mount bracket in the backbox.

Take a look at the schematic. That wire connects the ground pins coming in on J4 to the large ground plain on the board. Should be connected to pins 18 and 19 only.

 

[Zinfer]

Oh so it came like that from the factory? Well that addresses that. Thanks man.
I downloaded the manual for Mr & Mrs and now have the pinouts for J4.
Not sure how much it would prove but I am going to wire up those pins with the +5's, +12 and ground voltages directly to J4 rather than just to tap locations to see if there are any board problems at all. I'm going to tear into it tonight, get the playfield off or otherwise out of the way and see if I can find those voltages at the rectifier underneath the playfield.

Take a look at the schematic. That wire connects the ground pins coming in on J4 to the large ground plain on the board. Should be connected to pins 18 and 19 only.

 

[Zinfer]

Thanks Radish,
I've a feeling once I find the right area of the problem the whole thing will come to life. Any help is good help.

My Rapid Fire is currently torn apart while I'm rebuilding the ball feeder mech, but if you are still having issues once I get it back together I'd be more than happy to do some apples to apples voltage comparisons.

 

[Zinfer]

Ok, what did I do? I just noticed R11 getting very hot to the touch. I think I'm about to lose a resistor on the MPU. Ah well, ordered the corrosion kit from Great Plains as I don't have all the components necessary to replace those that should be.

 

[Zinfer]

Alright I may have something here. I pulled the Rectifier board and cleaned it up. Threw some new heat sink grease on. It all looked fine. No bad burn areas, fuses all fine, diodes look good. Powered the cabinet up and checked all test points. All were well within parameters except for one. TP3 I read up on, was apparently supposed to be like, 11.9vdc however I'm only getting 1.051vdc from TP3.
Can anyone confirm the voltage on the rectifier board TP3?
TP1- 6.5vdc
TP2- 230vdc
TP3- 11.9vdc
TP4- 6.5vdc
TP5- 43vdc

 

[Lindsey]

Alright I may have something here. I pulled the Rectifier board and cleaned it up. Threw some new heat sink grease on. It all looked fine. No bad burn areas, fuses all fine, diodes look good. Powered the cabinet up and checked all test points. All were well within parameters except for one. TP3 I read up on, was apparently supposed to be like, 11.9vdc however I'm only getting 1.051vdc from TP3.
Can anyone confirm the voltage on the rectifier board TP3?
TP1- 6.5vdc
TP2- 230vdc
TP3- 11.9vdc
TP4- 6.5vdc
TP5- 43vdc

TP3 on the rectifier board should be approx. 12VDC. This information can be found on the rectifier board schematic. That's the voltage that will be the input of the +5VDC voltage regulator on the regulator/driver board (also found at TP5 on the regulator/driver board. If that voltage is low you can be sure that the +5VDC will also be low or not present. That would explain your MPU problem.

 

[Zinfer]

http://www.youtube.com/watch?v=xos2MnVxe-c

CR6 was the culprit. A shorted diode. Replaced and reassembled the cabinet, powered up and low and behold! It lives!
Other than some tweeking problems (the ball loader seems to have some problems loading fast enouph and occasionally the game shuts and reboots during shots) I think I'm well on my way to having my first working pinball! Yay!
Thanks for everything Lindsey, you were a great help.

TP3 on the rectifier board should be approx. 12VDC. This information can be found on the rectifier board schematic. That's the voltage that will be the input of the +5VDC voltage regulator on the regulator/driver board (also found at TP5 on the regulator/driver board. If that voltage is low you can be sure that the +5VDC will also be low or not present. That would explain your MPU problem.

 

[Zinfer]

Well shucks I just jinxed myself. I think the resets were occurring because one or both of the PIA's were dieing. This thing must have been down for quite a while.
I've now got 3 flashes in which it then blinks the score display and it resets over again.
Sometimes it gets past the 3 blinks and it starts the game up, I start a game and begin shooting, then boom it resets.
It was fun playing it for 10 seconds at a time though.